This laboratory will serve as a central diagnostic laboratory for the detection of mycoplasma contamination in specimens submitted for this purpose by other contractors or NCI intramural scientists in the Viral Oncology Program. Samples from other than the NCI or Viral Oncology contractors will not be tested unless previously cleared by the Office of Resources and Logistics and/or the NCI Project Officer. This restriction is primarily due to the limitation of funds for this service. Upon request, serological identification of isolates will be made as to species. In addition, the Principal Investigator consults, upon request, with other scientists or laboratories within the Virus Cancer Program or at NCI regarding problems associated with actual or suspect mycoplasma contamination. During the period 5/16/74-1/15/75 (8 months), the contractor has received 1297 specimens from the Program and were assayed for mycoplasmas; 117 specimens were positive for mycoplasma. There were three requests for species identification.